Enhancing Thermogalvanic Efficiency through Electrostatic Interaction in Cationic Hydrogels.

Thermoelectric hydrogels have the potential to be used in energy conversion devices for harnessing ubiquitous low-grade heat and generating useful electricity. This can be achieved through the use of thermogalvanic cells based on redox chemistry. While significant attention has been focused toward maximizing voltage for a given temperature gradient in liquid-based thermocells, it is crucial to consider both voltage and current density for accurate power output estimation in the case of gel-based thermocells. Here, we analyze the influence of the functional groups and the redox pair concentration over the voltage and current density in two different hydrogels. Our results confirm a path to enhance the current density in thermogalvanic hydrogels by incorporating a cationic pair into a cationic electroactive network (CN). This approach facilitates the movement of redox pairs, therefore increasing the power density output.